* {
    padding: 0;
    margin: 0;
}

body {
    background-color: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100vw;
    height: 100vh;
}

ul {
    width: 60vw;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

li {
    list-style: none;
}

a {
    position: relative;
    color: #FFF;
    text-decoration: none;
    padding: 6px 18px;
    /* background-color: #3ce745; */
    transition: background-color 0.8s;
}

a:hover {
    background-color: #e74c3c;
}

a::before {
    position: absolute;
    content: "";
    width: 18px;
    height: 18px;
    border: 2px solid #e74c3c;
    border-width: 0 0 2px 2px;
    left: 0;
    bottom: 0;
    opacity: 0;
    transition: 0.2s;
}

a::after {
    position: absolute;
    content: "";
    width: 18px;
    height: 18px;
    border: 2px solid #e74c3c;
    border-width: 2px 2px 0 0;
    top: 0;
    right: 0;
    opacity: 0;
    transition: 0.2s;
}

a:hover::before {
    left: -12px;
    bottom: -12px;
    opacity: 1;
}

a:hover::after {
    top: -12px;
    right: -12px;
    opacity: 1;
}